The basic economics is the study of, and the Economy is a process where people ears their livelihood.
Human being has unlimited wants; however, to fulfil those needs resources are limited. So we have to choose short everyone has unlimited wants and income is low so it has to make a choice. That is with every Economy, and this is known as the central problem of Economy as this problem arises with every Economy.
What to produce, how to build, and for whom to produce.
To solve these problems, PPC was invented. PPC shows all the best possible combination of two goods that an economy can produce with the given resources and available technology.